Unable to read manufacturing protection key on closed IMX8MQ via OP-TEE

[fourtrax1]

I am trying to read the manufacturing protection public key via OP-TEE.

Before closing the system for secure boot, the xtest for this feature ran successfully.

However, after closing the system, the test simply hangs with the following error:

[ 62.432015] INFO: task hwrng:265 blocked for more than 30 seconds.

[ 62.438256] Not tainted 6.1.86 #1

[ 62.442141] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

[ 62.450012] task:hwrng state:D stack:0 pid:265 ppid:2 flags:0x00000008

[ 62.458416] Call trace:

[ 62.460897] __switch_to+0xe0/0xf8

[ 62.464353] __schedule+0x458/0x538

[ 62.467864] schedule+0x5c/0xb0

[ 62.471046] schedule_timeout+0x3c/0xec

[ 62.474929] __wait_for_common+0x8c/0x11c

[ 62.478982] wait_for_completion+0x24/0x2c

[ 62.483122] caam_rng_read_one.constprop.0+0x214/0x260

[ 62.488310] caam_read+0x48/0xb4

[ 62.491563] rng_get_data+0x58/0x98

[ 62.495097] hwrng_fillfn+0x94/0x104

[ 62.498717] kthread+0xdc/0xec

[ 62.501819] ret_from_fork+0x10/0x20

[ 62.505448] INFO: task kworker/u9:0:540 blocked for more than 30 seconds.

[ 62.512273] Not tainted 6.1.86 #1

[ 62.516144] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

[ 62.524006] task:kworker/u9:0 state:D stack:0 pid:540 ppid:2 flags:0x00000008

[ 62.532411] Workqueue: kverityd verity_work

[ 62.536648] Call trace:

[ 62.539106] __switch_to+0xe0/0xf8

[ 62.542550] __schedule+0x458/0x538

[ 62.546082] schedule+0x5c/0xb0

[ 62.549266] schedule_timeout+0x3c/0xec

[ 62.553154] __wait_for_common+0x8c/0x11c

[ 62.557225] wait_for_completion+0x24/0x2c

[ 62.561366] crypto_wait_req+0x28/0x3c

[ 62.565157] verity_verify_io+0x258/0x3ac

[ 62.569209] verity_work+0x24/0x40

[ 62.572652] process_one_work+0x1e8/0x2a8

[ 62.576704] worker_thread+0x1d4/0x26c

[ 62.580493] kthread+0xdc/0xec

[ 62.583571] ret_from_fork+0x10/0x20

I added the Unlock section to the CSF, but it didn't help:

[Unlock]
Engine = CAAM
Features = MFG

Do you have any idea what could be causing this hang and why it only happens after closing the device?

[Harvey021]

What does it look like to read from uboot?

Regards

Harvey

[fourtrax1]

Hi Harvey, thanks for your reply. We are using barebox which does not support reading it, that is why I was planning to read it via OP-TEE.